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カンボジアの豆知識 (10): カンボジアの不思議な湖

Fun Facts About Cambodia (10): Cambodia’s Spectacular Lake

(English report follows after Japanese)

Photo of Tonle Sap. Photo Credit: Best Price Travel.







Each year when it comes to the rainy season (from May to November) in Cambodia, a spectacular phenomenon will occur. With an increase in rainfall, the Tonle Sap River, which is connected to Tonle Sap Lake, will flow in a reverse direction, and the Tonle Sap Lake will expand to more than 6~7 times of its normal surface area (approx. 2700 km²).


Now you may ask, why does the river reverse its direction in the first place? During the dry season (from December to April) in Cambodia, under normal circumstances, water will flow down from Tonle Sap Lake, through the Tonle Sap River, and into the connecting Mekong River. However, when it enters the wet season, due to heavy amount of rainfall brought about by the monsoon rain, the Mekong River reaches its capacity limit, and excess water are being pushed back into Tonle Sap River, causing a reverse in the river’s flow direction. This eventually results in large amount of water to flow into Tonle Sap Lake as well, and flooding the surrounding land and forest. Once after the monsoon has subsided in around November, the Tonle Sap River reverses to its normal flow direction again, and so is Tonle Sap Lake, which will gradually return to its usual surface area until February.


Another fact about Tonle Sap that is good to know. Limited to only during the wet season, one is able to hitch on a boat ride and sight-see around Tonle Sap. Through a boat tour, it is possible to reach and explore the Floating Villages of Tonle Sap (where you can find school, hospital and church there!). As well as being able to observe the natural wildlife habitat of Tonle Sap, such as birds, snakes and crocodiles. Furthermore, besides going by road or air, one can also choose to go by the waterway method, crossing Tonle Sap to get from Phnom Penh to Siem Reap with boat cruises available.


If you have some time to spare, it certainly might be a great way of making your trip an even wonderful one by taking a slow ride on the boat and bask in the beautiful nature of Tonle Sap.



  1. Facts And Details, Cambodia Tonle Sap

  1. Wikipedia, Tonle Sap

  1. タビナカマガジン、シェムリアップから足を延ばしてトンレサップ湖へ!